Application of Probiotic, Prebiotic and Synbiotic for the Control of Streptococcosis in Tilapia Oreochromis niloticus

One of the fish diseases that is becoming the main problem in tilapia culture is streptococcosis caused by Streptococcus agalactiae. Application of probiotic, prebiotic and synbiotic are expected to be an alternative for controlling the disease. The purpose of this study was to examine the effectiveness of the administration of probiotic, prebiotic and synbiotic through artificial feed to control streptococcosis in tilapia. This study consisted of five treatments with three replications, namely positive control, negative control; 1% probiotic treatment; 2% prebiotic treatment and synbiotic treatment (1% probiotic and 2% prebiotic). Results showed that fish survival rate before the challenge test for all treatments was between 95 and 100%. Growth and feed conversion ratios in probiotic, prebiotic and synbiotic treatments were better than that of the controls. After the challenge test, the fish survival rate in probiotic, prebiotic and synbiotic treatments were 74.08, 74.08 and 85.19%, respectively; whereas, in the positive control it was only 18.52%. Results showed that S. agalactiae bacteria could be found in the brain, kidney, liver and eyes. The number of S. agalactiae bacteria and the damage level of various target organs in probiotic, prebiotic and synbiotic treatments were lower than that of positive control.